Otto sohst



Patented Dec. 11, 1923..

UNITED STATES PATENT OFFICE.

OTTO S OHST, OF HOCHST-ON-THE-MAIN, GERMANY, ASSIGNOR TO FARBWERKE VORM.

TTO'N" OF GERMANY.

PROCESS OF PREPARING SULPHONIC ACIDS OF THE ARYLIDES OF 2.8-OXYNAPHTHOIC ACID.

No Drawing.

To all whom it may concemi:

Be it known that I, Orro SoHs'r, a citizen of Germany, residing at Hochst-on-the- Main, Germany, have invented certain new and useful Improvements in a Process of Preparing Sulphonic Acids of the Arylides of 2.3-Oxynaphthoic Acid,- of which. the following is a specification.

I have found that the arylamides of 2.3-oxynaphthoic acid of the general formula wherein R represents any aryl residue which may be substituted once or several times by av methyl-, chlorine-, nitro-, alkyloxy-, or any other groupcan be easily converted by the action of sulfuric acid into hitherto unknown sulphonic acids which may be used for the manufacture of dyestuffs.

These sulphonic acids, to which the general formula:

may be attributed, and which contain the sulfo group in the fi-oxynaphthoic acid residue. are, when dry, generally light-grey powders. Their solution in hot water tends, after cooling, to solidify into a transparent gelatinous mass. Their alkali salts are readily soluble in water with a faint-yellow color.

The proportional quantities, the concen- Application filed Kay 13, 1922. Serial No. 560,748.

until the whole is dissolved and a test, when put in a diluted solution of sodium carbonate, shows a clear solution. When pour-' ing the product of the reaction after it has been cooled down to 20 (3., into a salt solution, obtained from 75 kg. of common salt and 300 kg. of water, a voluminous lightgrey precipitate results, which can be filtered off and, after being repeatedly treated with a salt solution and filtered, directly used as a paste. I

2. 30 kg. of (i-oxynaphthoic acid-4-chlor- 2-toluidide are introduced while stirring into about 90 kg. of sulfuric acid monohydrate and this mixture is heated for a short time to 90 C. until the whole is clearly dissolved and a test, when put in a diluted solution of sodium carbonate, shows a clear solution. The product thus obtained is cooled down to 20 C. and poured into a salt solution prepared from 75 kg. of common salt and 300 kg. of water, whereupon the sulphonic acid separates in the form of a light-grey, granular precipitate which can be filtered off, washed with a solution of common salt and dried. It yields a lightgrey powder which is readily soluble in, hot water. On cooling, the solution solidifies so as to form a transparent jelly. Its solution rendered alkaline with sodium carbonate has a faint-yellow color. If instead of the above mentioned B-oxynaphthoic acid-4-chlor-2- toluidide another arylide, such. for instance,

as B-oxynaphthoic-ortho-anisidide or tl-oxynaphthoic acid-m-nitranilide, are used, sulphonic acids of similar properties are obtained.

Having now described my invention what I claim is:

As new products, the sulphonic acids of the general formula:

wherein R represents any aryl residue which may be once or several times substituted by a -methyl-, chlorine-, nitro-, alkyloxy of which in hot water generally solidifies or any other group and wherein the sulfo into a transparent gelatinous mass, their group is contained in the (l-oxynaphthoic alkali salts being readily soluble in water 10 acid residue-which sulphonic acids can with a faint yellow colour.

5 be obtained by treating the arylides of In testimony whereof, I afiix my signa- 2.3-oxynaphthoic acid with sulfuric acid and ture. form, when dry, grey powders the solution OTTO SOHST. 

